THE GUN RIGHTS lobby has spent considerable time and energy in pursuit of one goal: crippling the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF). It has largely succeeded — and with dire consequences.

Concerned to the point of paranoia about the erosion of the constitutional right to keep and bear arms, the National Rifle Association and far too many lawmakers have fought against virtually every proposal to empower the bureau to better track and crack down on illegal firearms. They have won reductions in the ATF’s already meager budget. They have restricted the bureau’s ability to share information with other law enforcement agencies. They have kept the bureau rudderless for the past six years by blocking confirmation of new directors. And they continue to fight new rules that would allow the bureau to track bulk sales of long guns that have played a major role in the drug-fueled violence in Mexico.

Now, the very critics who have tied the bureau’s hands are expressing outrage over a novel, and we would agree questionable, ATF operation intended to curb gun smuggling into Mexico.

Operation Fast and Furious was launched in 2009 and was centered in the ATF’s Phoenix office, where agents surveilled straw purchases of AK-47 knockoffs and other high-powered weapons known to be favorites of the drug cartels. The agents did not try to seize the weapons but instead watched as straw buyers made repeated visits and passed firearms to third parties. In January, the Justice Department indicted some 30 relatively low-level individuals on charges of gun running and making straw purchases.

The ATF had hoped to move against higher-ups in the chain of command, but the operation went awry when the bureau lost track of 2,500 weapons, some of which have now been traced to criminal activity south of the border. Two such weapons were found in December at the scene of the murder of a U.S. Border Patrol agent.

The Justice Department’s Office of Inspector General and Congress are investigating, understandably. The probes could help to explain what went wrong and what could or should have been done differently. But Capitol Hill’s intense interest in the ATF should not stop there.

Lawmakers should give the ATF the tools it needs to fight illegal gun trafficking. They should enact stronger penalties for straw purchases and craft a federal gun-smuggling statute; close the gun-show loophole, which allows buyers under certain circumstances to purchase weapons without a background check; resuscitate the ban on assault weapons; and give the ATF the authority to collect data on multiple sales of long guns in border states. The Senate should move quickly to confirm a director for the long-leaderless bureau.

We may never know whether the bureau would have launched the Fast and Furious operation had it had other, more effective tools at its disposal. Those who would clobber the bureau for possible mistakes should look in the mirror and accept some responsibility for its failings.